1. Technical Field
The present invention relates to a light detector including a light receiving device, an optical position detection apparatus including the light detector, and a display apparatus with a position detection capability including the optical position detection apparatus.
2. Related Art
A light detector including a photodiode, a phototransistor, or any other suitable light receiving device is used as a variety of sensors and optical communication receivers. A light detector with a lens in which the lens provided in front of a light receiving device increases the sensitivity has been proposed (see JP-A-09-153646).
To detect the intensity of light incident in a wide range of directions by using a light detector, the directional characteristic of sensitivity as well as the level of sensitivity needs to be considered. The light detector with a lens described in JP-A-09-153646 cannot solve the problem of the directional characteristic of sensitivity. That is, a light detector is highly sensitive to light squarely incident on the light receiving device, whereas being not very sensitive to light obliquely incident on the light detector. Therefore, when the intensity of the incident light is monitored based on a detection result from the light detector, using the light detector with a lens described in JP-A-09-153646 is problematic in that a detected value of obliquely incident light is lower than the actual value.